Medical devices can be implanted in the bodies of patients for various purposes. Some medical devices detect physiologic events and may apply therapy in response to certain events of interest. For example, a cardiac pacemaker can detect a lull in the beating of the patient's heart and apply an electrical pulse to stimulate the heart into beating again. Implantable sensors are preferably small so that they can be maneuvered and deployed in areas of the human body that are difficult to access.
Implantable sensor devices typically include components that require power to operate. For example, the sensor may require some small amount of power to sense the physiologic parameter of interest (e.g., blood pressure). An implantable sensor device may also have the ability to transmit and receive data via communications circuitry that requires power. As such, implantable sensor devices typically include a battery.
Some implantable sensor devices are connected by wires to another device, such as pulse generator, which is also implanted in the body. The wires can be used for communication to and from the other device and/or for power delivery. These wires can add to the difficulty in maneuvering and deploying the implantable sensor in the body, particularly at locations that are not easily accessible.